Lead-202
Properties and data of the isotope 202Pb.
See also: list of Lead isotopes.
General data
Name of the isotope:Lead-202; Pb-202Symbol:202Pb or 20282PbMass number A:202 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:120Isotopic mass:201.972152(4) u (atomic weight of Lead-202)Nuclide mass:201.9271736 u (calculated nuclear mass without electrons)Mass excess:-25.94024 MeVMass defect:1.709290544 u (per nucleus)Nuclear binding energy:1592.19388599 MeV (per nucleus)
7.88214795 MeV (average binding energy per nucleon)Separation energy:SN = 8.741(14) MeV (first neutron)
SP = 6.049(15) MeV (first proton)Half-life:52.5(28) × 103 aDecay constant λ:4.186581506607 × 10-13 s-1Specific activity α:1254337490.2685 Bq g-1
0.0339010132505 Ci g-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.4705(17) femtometer fmYear of discovery:1954
Radioactive Decay
Half-life T½ = 52.5(28) × 103 a respectively 1.65564 × 1012 seconds s.
Decay mode | Daughter | Probability | Decay energy | γ energy (intensity) |
---|
EC | 202Tl | 99 % | 40(4) MeV MeV | |
α | 198Hg | 1 % | 2.589(4) MeV | |
Parent Nuclides
Direct parent isotopes are: 202Bi, 206Po.
Nuclear Isomers
Nuclear isomers or excited states with the activation energy in keV related to the ground state.
Nuclear Isomer | Excitation Energy | Half-life | Spin |
---|
202m1Pb | 2169.85(8) keV | 3.54(2) h | 9- |
202m2Pb | 4091.0+x keV | 110(5) ns | (16+) |
202m3Pb | 5251.0+x keV | 107(3) ns | (19-) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 120) and isobaric (same nucleon number A = 202) with Lead-202. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Z | Isotone N = 120 | Isobar A = 202 |
73 | 193Ta | |
74 | 194W | |
75 | 195Re | |
76 | 196Os | 202Os |
77 | 197Ir | 202Ir |
78 | 198Pt | 202Pt |
79 | 199Au | 202Au |
80 | 200Hg | 202Hg |
81 | 201Tl | 202Tl |
82 | 202Pb | 202Pb |
83 | 203Bi | 202Bi |
84 | 204Po | 202Po |
85 | 205At | 202At |
86 | 206Rn | 202Rn |
87 | 207Fr | 202Fr |
88 | 208Ra | 202Ra |
89 | 209Ac | |
90 | 210Th | |
External data and identifiers
Last update: 2020-10-22
Perma link: https://www.chemlin.org/isotope/lead-202
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